connection speeds

when ISPs refer to kbps they are not refering to kilobytes it's a measure of data trasfer speed. Modems, for example, are measured in Kbps.
One kbps is 1,000 bits per second and a Kb (kilobyte) is 1,024 bytes. Technically kbps, should be spelled with a lowercase k to indicate that it is decimal but almost everyone spells it with a capital K.
 A kilobit per second is a unit of data transfer rate equal to:

• 1000 bits per second or
• 125 bytes per second.

A megabit per second is a unit of data transfer rate equal to: 1,000,000 bits per second or 1,000 kilobits per second or 125,000 bytes per second. So if I had a 5 mbps connection i could trasfer up to 625000 bytes per second or 610 Kilobytes per second or 0.6 MB per second